The statement best supported by the chart is B. Slavery was a profitable part of the triangular trade.
How to conclude this on slavery?
This conclusion can be drawn from the chart's depiction of the Atlantic slave trade, where Africa sent slaves to the Americas, and in return, the Americans sent raw materials to Europe.
The triangular trade system was driven by economic motives, and the chart illustrates that the exchange of enslaved people was a central and profitable component of this system.
The flow of goods in the chart clearly highlights the economic transactions involved in the trade, reinforcing the idea that slavery played a significant and profitable role in the triangular trade.